Printed solar cells require less material than expected
A solar cell that can be applied to a film like newspaper printing - that sounds tempting. Organic solar cells could make exactly that possible. They are not made from the expensive silicon of conventional solar modules, but from special plastics. Researchers at Chemnitz University of Technology have now discovered how these cells can still function well even if one of their most important components is reduced to a minimum.
Organic solar cells consist of two materials that generate electricity together. One emits electrons (donor), the other absorbs them (acceptor). It is this interaction that makes electricity generation possible. When light hits the cell, an electric current is generated. Until now, a balanced mixture of both substances was considered a prerequisite for good performance.
Surprisingly good despite less material
The Chemnitz team led by Prof. Dr. Carsten Deibel has now questioned this assumption and reduced the donor content. The result surprised the researchers. Although they continued to reduce the amount of material, the solar cells worked much better than expected. Even with a proportion of just one percent, the solar cell still worked surprisingly reliably.
The investigations show that the amount of material is not the only decisive factor. What is particularly important is how the various components are arranged inside the solar cell. According to Prof. Carsten Deibel, this internal structure largely determines how efficient an organic solar cell can be.
The results suggest that organic solar cells could make do with significantly less material than previously assumed. This in turn would make production cheaper and conserve resources.
The basis for cheaper solar modules
The findings are not only interesting in theory. Organic solar cells can be produced using printing processes, similar to how a newspaper is printed. This makes them potentially much cheaper than conventional solar modules. They are also seen as a promising addition to traditional solar cells. They are lightweight, flexible and could be used in the future on facades, vehicles or portable electronic devices, for example.
The study was published in the specialist journal "Advanced Materials" and was carried out as part of the DFG research group POPULAR, which is coordinated by Chemnitz University of Technology and funded with around five million euros. Fourteen scientists from Germany and the UK are involved, including researchers from TU Dresden and the Leibniz Institute for Solid State and Materials Research Dresden (IFW). Together, they are working to better understand solar cells from the printer and to further develop them for later series production.
Original publication:
Chen Wang, Maria Saladina, Carsten Deibel, et al: Rethinking charge transport: Donor dilution reshapes limits of organic solar cells. Advanced Materials e23681 (2026).
